Fig. 3

Muscle-derived DMD mRNA studies. A RT-PCR amplification of the aberrant DMD transcripts from patient 1 showed that the lower band was shorter than the expected band, while the upper band was almost the same size as the expected band. B Direct Sanger sequencing of the aberrant DMD transcripts could not recognize the overlapping sequences. TA cloning of the aberrant DMD transcripts revealed three transcripts, including the missense transcript (normal splicing of DMD exons 19 to 20; C), the skipping of exon 19 (D), and a 7 bp deletion of exon 19 (E). F The schematic of exon 19 skipping caused by the c.2380G > C variant in DMD. G The schematic of the 7 bp truncation of exon 19 caused by the c.2380G > C variant in DMD. H RT-PCR amplification of muscle mRNA from patient 2 showed the aberrant DMD transcript was shorter than the expected band. I Sanger sequencing of the aberrant DMD transcript revealed a 53 bp deletion of exon 35. J The schematic of the 53 bp truncation of exon 35 caused by the c.4977C > G variant in DMD. K RT-PCR amplification of muscle mRNA from patient 3 showed the aberrant DMD transcript was almost the same size as the expected band. L Sanger sequencing of the aberrant DMD transcript revealed a 5 bp deletion of exon 38. M The schematic of the 5 bp truncation of exon 38 caused by the c.5444A > G variant in DMD. The canonical GT–AG splice site pairs at the splice junctions were in red fonts. RT-PCR, reverse transcription-polymerase chain reaction; bp, base pair; *, premature termination codon; 5′ ss, donor splice site; Ctr1, a normal control; Blank, a reagent control; HSF, Human Splicing Finder; MaxEnt, Maximum Entropy